Mack was the No. 5 pick in the 2014 NFL draft, and McKenzie has high expectations for the rookie out of Buffalo.

"He's reminded me of Clay Matthews from Day 1," Oakland general manager Reggie McKenzie said. "He's one of those guys that knows how to set the edge, and he has length and power and some tools to rush the passer."

McKenzie was the director of player personnel for Green Bay when it drafted Matthews in 2009. He said the comparison extends beyond their body-types and into their on-field personalities.

"That's what Clay was, you don't have tell him to go sic 'em," McKenzie said. "He just innately does that. Khalil is that same way."